Figure 1. Radionuclide scan demonstrates a "hot" nodule in the right lobe of the thyroid gland with suppression of all remaining thyroid tissue.
Figure 2."Hot" nodule. Treatment was a right thyroid lobectomy.
Palpable solitary thyroid nodules are present in approximately 5% to 6% of American women, a rate that is at least 4 times greater than that noted in men in several studies.1 Despite the small number of patients who develop thyroid cancer in the United States each year (estimated 18 400 in 2000), many thyroidectomies in the past were performed to rule out a malignant tumor in such nodules.2 The availability of early and accurate diagnosis from FNA, however, has significantly decreased unnecessary thyroidectomies for benign nodules over the past 25 years.3,4 At present, indications for operation in patients with solitary thyroid nodules include the following:
Nondiagnostic (15%-20%) or suspicious (10%) FNA
Malignant cells on FNA (4%)
Growth of nodule (use ultrasound to rule out hemorrhage into the nodule) in patient receiving thyroxine therapy
Symptomatic (pain, tracheal deviation with respiratory symptoms, odynophagia) nodule in patient without evidence of hemorrhage into the nodule
Patient request to improve cosmetic appearance
Toxic (hyperfunctioning) adenoma
Clinical hyperthyroidism from a hyperfunctioning adenoma develops gradually over time. Asymptomatic patients with reasonably normal TSH levels associated with an FNA-benign nodule can be observed according to a standard endocrinology textbook. When TSH levels fall below normal levels and the patient is symptomatic, current therapeutic options for a toxic adenoma include antithyroid drugs, radioactive iodine, percutaneous injection of ethanol, and thyroidectomy.5
Antithyroid drugs have the disadvantage of recurrent hyperthyroidism when administration is stopped, but they have been used before administration of radioactive iodine or thyroidectomy in elderly patients. Radioactive iodine should be taken up by the hyperfunctioning nodule when the remainder of the thyroid gland is suppressed (Figure 1). Five to 15 mCi 131 I should result in a cure rate of 90% in elderly patients.6,7 Multiple percutaneous injections of sterile 95% ethanol into the toxic adenoma with ultrasonography resulted in a cure rate of 78% in an Italian study (median follow-up, 2.5 years).8
Toxic adenomas are the third most common indication for surgical intervention for hyperthyroidism.9,10 Depending on local referral patterns to endocrine surgeons, operations for toxic adenoma account for 5% to 20% of current operations for hyperthyroidism. Thyroidectomy is generally recommended for children, adults, and should be considered for otherwise healthy elderly patients with large nodules. Most patients referred from endocrinologists return to a euthyroid state by the administration of antithyroid drugs. Preoperative administration of a saturated solution of potassium iodide is unnecessary. Either nodulectomy or subtotal vs total thyroid lobectomy can be performed (Figure 2). Thyroidectomy is immediately curative in patients who are euthyroid at the time of operation. Postoperative and late rates of hypothyroidism are reported to be 10% to 20% in the medical literature.7,11
Corresponding author: David V. Feliciano, MD, Grady Memorial Hospital, Thomas K. Glenn Memorial Bldg, Department of Surgery, 69 Butler St SE, Third Floor, Atlanta, GA 30303.
Image of the Month. Arch Surg. 2001;136(2):240. doi: